A336759 a(n) is the smallest positive number that is the sum of no fewer than n distinct repdigits.

1, 10, 21, 309, 2108, 21996, 220884, 2111105, 21866660

Offset: 1

Author

Falcon Shapiro, Aug 03 2020

Keywords

• nonn
• base
• more

Comments

Conjecture: the sequence is infinite.

Examples

			10   is the sum of 2 distinct repdigits:                   9 + 1
21   is the sum of 3 distinct repdigits:              11 + 9 + 1
309  is the sum of 4 distinct repdigits:        222 + 77 + 9 + 1
2108 is the sum of 5 distinct repdigits: 1111 + 888 + 99 + 9 + 1
All numbers less than 10 can be summed with less than 2 distinct repdigits.
All numbers less than 21 can be summed with less than 3 distinct repdigits.
		

Crossrefs

Cf. A010785, A336748.

Extensions

a(7)-a(9) from Sean A. Irvine, Aug 29 2020